Gaming machines, such as slot machines, video poker machines, and the like, have been a cornerstone of the gaming industry for several years. Generally, the popularity of such machines with players is dependent on the likelihood (or perceived likelihood) of winning money at the machine and the intrinsic entertainment value of the machine relative to other available gaming options. Where the available gaming options include a number of competing machines and the expectation of winning each machine is roughly the same (or believed to be the same), players are most likely to be attracted to the most entertaining and exciting of the machines.
Consequently, gaming terminal operators strive to employ the most entertaining and exciting terminals available because such terminals attract frequent play and, hence, increase profitability for the operators. Thus, in the highly competitive gaming terminal industry, there is a continuing need to develop new types of games, or improvements to existing games, that will enhance the entertainment value and excitement associated with the games.
One concept that has been successfully employed in existing gaming terminals to enhance player entertainment is the use of a secondary or “bonus” game which may be played in conjunction with a “basic” game. The bonus game may include any type of game, either similar to or entirely different from the basic game, initiated by the occurrence of certain pre-selected events or outcomes of the basic game. Such a bonus game has been found to produce a significantly higher level of player excitement than the basic game alone because it provides an additional chance to play, which increases the player's overall expectation of winning. Moreover, bonus games often provide a greater expectation of winning than the basic game alone. According to one type of bonus game, a plurality of player-selectable symbols or windows are provided and the selection of which reveals a bonus-credit award that is initially covered by the symbol. The player continues to make selections and accumulate awards until an end-bonus outcome is uncovered. Thus, if a player initially selects a symbol covering the end-bonus outcome, the player receives no bonus award. This selection-type game, wherein a selection may award credits or end the game, is generally considered to have a high volatility index. “Volatility index” is a mathematical value that is the industry standard for measuring distribution of sizes and probabilities of slot machine payoffs and is described in further detail in U.S. Pat. No. 6,302,791, which is incorporated herein by reference in its entirety. For example, standard slot machines have a relatively steady payoff progression and, thus, are considered to have low volatility indices, which means that there is a relatively steady progression of many payoff values from the lowest to the highest, with each payoff corresponding probability decreasing as the value of the payoff increases. On the other hand, the described selection-type bonus game has a high volatility index. “Expected value” (“EV”) is another mathematical value used in the industry to describe the probability-weighted average of all possible outcomes of a chance event or, stated differently, the EV may be defined as the percentage of the total wager that the machine will pay out over the cycle of the game, where the cycle is defined to be the set of all possible outcomes. In one respect, the volatility is used to refer to the standard deviation of the distribution of possible values about the expected value.
Some conventional gaming terminals provide gaming features that provide a better than average chance of winning, but fail to exceed a potential 100% payout (i.e., a 50/50 chance of the player or the house winning on a particular play).
The gaming experience may be advantageously enhanced by selective manipulation of the volatility and expected value to provide increased excitement and entertainment value over existing gaming terminals.